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Area forecast discussion 
National Weather Service Wakefield Virginia
550 PM EDT Friday Aug 22 2014

Synopsis...
a frontal boundary remains nearly stationary across the region
through Saturday. High pressure from New England slowly builds into
the area Saturday night into Sunday...before settling over the
Piedmont early next week.

&&

Near term /until 6 am Saturday morning/...
the latest surface analysis shows weak low pressure off the Virginia/NC
coast...with a stationary front extending back through eastern Virginia and
then northward into central PA. Aloft...northwest middle/upper flow continues
over the middle Atlantic region on the northern periphery of a ridge
centered over the lower Mississippi Valley. The greatest
concentration of showers and embedded thunderstorms has been from the Northern
Neck to the Eastern Shore. This is occurring immediately NE of the
surface boundary where low-level convergence has combined with
modest lift associated with an upper jet maximum. Locally heavy rainfall
is occurring with radar estimated rates of 1-2in/hr. NAM bufr
soundings seem to handle the Omega profile rather well and indicate
this lift diminishes over the next few hours. Otherwise...another
wave over the central Appalachians should result in an increase in
coverage of showers and embedded thunderstorms across southern portions of the
area during the late afternoon and evening hours. Forcing for ascent
wanes after midnight and hence probability of precipitation diminish along with the
potential for thunder. The sky should remain mostly cloudy with lows
ranging from the upper 60s to low 70s.

&&

Short term /6 am Saturday morning through Monday/...
chance probability of precipitation along with considerable cloud cover will be maintained for
Saturday as the remnant boundary remains near the local area. The
potential for thunder will be confined away from the coasts due to
east-northeast flow with high pressure building over New England. The high
surges south-southwest over the area Saturday night into Sunday with the surface
ridge axis settling over the Piedmont by Monday. This will produce a
drying trend along with a NE wind that should be rather breezy along
the coast. Partly to mostly sunny conditions are expected by
Sunday...with mostly clear/sunny conditions by Sunday night and
Monday.

Highs will be below seasonal averages Saturday through Monday
(around -1 St dev). Saturday highs will range from 80-85 (upper 70s
along the Atlantic coast)...with upper 70s to low 80s Sunday and
Monday. Lows should be in the middle/upper 60s Sunday morning...with
low/middle 60s expected Monday morning.

&&

Long term /Monday night through Friday/...
surface high pressure and upper level ridging along the eastern Seaboard
is expected to keep tropical cyclone activity well off the coast by
about 500-600 miles. This pattern will maintain a cooler airmass
over the area through Wednesday before the ridge axes at the surface and aloft
aloft begin to shift just east of the forecast area...and moving offshore by
Thursday. The forecast is generally dry through the extended forecast
periods due to well-established subsidence through the atmospheric
profile...however a few showers cannot be ruled out near the far southeast
Virginia/NE NC coast on Wednesday due to the potential for wraparound moisture
from the tropical system passing well to the east. High and low
temperatures will run below normal from Monday night through Wednesday night
(lows in the 60s...upper 50s far western counties/highs in the low-middle
80s...mid-upper 70s beaches) and then rebound toward seasonal normals
Thursday/Thursday night (highs in the middle-upper 80s...upper 70s-lower 80s
beaches/lows in the middle-upper 60s...around 70 beaches).

&&

Aviation /22z Friday through Wednesday/...
a frntal boundary is stalled over the middle Atlantic with hi pressure
located over the NE states. Isolated/scattered rain showers/thunderstorms can be expected
mainly late in the day and during the eveng hours...but chance is
not hi enough to warrant a mention in the tafs at this time.

Outlook...shra/tstm chances continue into Saturday with dry
weather forecast beginning Sunday. MVFR/IFR due to stratus or fog
will be a potential a few hours around sunrise through Sunday
morning.

&&

Marine...
Small Craft Advisory headlines issued for coastal waters and southern ches Bay Sat afternoon
through sun.

A stationary frontal boundary will slowly drift southward across the southern
waters tonight as low pressure deepens off the coast. Meanwhile...a
weak backdoor cold front will drop into the area late tonight into
Sat. Northerly winds around 10-15 knots will be common ahead of the
front...then they will turn to the north-NE behind it as high pressure
ridges down over the waters. A period of persistent onshore winds
will result in prolonged Small Craft Advisory conditions for the coastal waters and
southern ches Bay...mainly due to elevated seas/waves (4-5ft/3-4ft
respectively). Winds will average 15-20kt ocean and 10-15kt
Bay/rivers/sound. Gusts may reach 25 knots at times over coastal
waters but main focus of Small Craft Advisory will be on seas of 5 feet. Given the
persistent onshore fetch...it is possible for seas to reach 6 feet
near buoy 44009 Sat evening during a weak push of cold air advection. Currituck
Sound and the mouth of the James River may be experience a brief
period of low-end Small Craft Advisory winds (15-20kt) on sun from daybreak until
sunset but decided to hold off on headlines for these areas for
now. Although current headlines end at 8pm Sun night...there is a
very good chance that Small Craft Advisory flags will be extended through Monday. High
pressure builds into the region Monday/Tuesday but a tropical system is
expected to pass about 500-600 miles east-southeast of the middle Atlantic
coast during this time. Swell from this system...in addition to
continued onshore winds...could keep seas elevated through Monday
before seas begin to subside.

&&

Akq watches/warnings/advisories...
Maryland...none.
NC...none.
Virginia...none.
Marine...Small Craft Advisory from 5 PM Saturday to 8 PM EDT Sunday for
anz632-634.
Small Craft Advisory from 8 PM Saturday to 8 PM EDT Sunday for
anz654.
Small Craft Advisory from 2 am to 8 PM EDT Sunday for anz656-
658.
Small Craft Advisory from 2 PM Saturday to 8 PM EDT Sunday for
anz650-652.

&&

$$
Synopsis...ajz/alb
near term...ajz
short term...ajz/alb
long term...bmd
aviation...mas/dap
marine...bmd

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